Maxtor Personal Storage on Mac

[Ether]

I've never had a Mac, so I won't be much of a practical help here, but I guess that the drive is formatted as NTFS (Windows format) and that's why Mac OS won't write to it.

1. You can try to install drivers that support writing, but maybe you'd prefer someone else (more computer savvy) to do it. Just a quick Google search for NTFS and Mac will get you lots of results.
2. Or you could reformat the drive as FAT - that way the drive would be accessible on practically any system, including Mac OS. (Just copy all your files to the computer, reformat using the Disk Utility, and copy the data back.)

As for the Disk Utility greyed out, I have no idea. Try Unmounting the volume first. Maybe if you could post a screenshot of the Disk Utility, I could figure out what's wrong.